It is known that an elevator system having an elevator cabin transports users between floors of a building. To this end, the floors and/or the elevator cabin is/are provided with call input apparatuses which the users can use to make call inputs. On the basis of the call inputs, an elevator controller actuates an elevator drive for the elevator cabin and a door drive for the elevator cabin such that the users can enter the elevator cabin and are transported by the elevator cabin between floors of the building.
To provide for equality of users with handicaps, European standard 81-70 prescribes a handicapped persons pushbutton for the call input. Pushing the handicapped persons pushbutton puts the elevator system into a special mode of operation. In this special mode of operation, elevator doors on the floors and/or elevator cabins are open and/or closed more slowly and users with handicaps are provided with feedback from the call input by means of visual and/or audible signals.
The document US 2002/0191819 A1 describes a way of detecting elevator users using a wheelchair. This involves taking images of elevator users in the space in front of an elevator system and using the position of the face to infer a wheelchair user.
The document US 2004/0022439 A1 describes a method for distinguishing between people who are able to walk and people using a wheelchair. Images are used to ascertain a 3D model of a recorded person and to determine whether or not the person is a person with a wheelchair.
The document JP 2002211833 discloses a method for verifying a wheelchair user when the latter has pushed a special key on an elevator control unit. Pushing the special key indicates to the elevator system that the passenger is a wheelchair user. When the special key has been pushed, the person who has pushed the switch has an image taken by means of a camera, and it is verified whether the person is actually a wheelchair user.
The document JP 11268879 describes how disabled people are detected by means of two cameras as soon as they push a switch on an elevator control unit and how the elevator system executes the elevator journey in a special mode when a disabled person has been detected.
The document U.S. Pat. No. 5,192,836 describes how the elevator which executes a journey requested by a disabled person is selected from a group of elevators. In order to indicate that the person requesting the elevator journey is a disabled person, the requesting person pushes an additional key on the control unit of the elevator system.
The document U.S. Pat. No. 5,323,470 describes a method for tracking the face of a patient in real time using cameras so that a patient can be fed by a robot.
The document US 2006/0011419 A1 discloses how an elevator control unit has an arrangement of switching keys with an optical sensor which are able to be activated contactlessly.
The document U.S. Pat. No. 6,161,655 describes an elevator control switch which can be operated contactlessly. Infrared radiation is emitted by the switch. If a potential passenger keeps his hand in front of the elevator control switch, the infrared radiation is reflected and hence the switch is activated.
The specification EP1598298A1 shows an elevator system having a call input apparatus in the elevator cabin. The call input apparatus has a touch screen, which touch screen is not compliant with EN81-70, since it does not have a handicapped persons pushbutton. As a solution which is compliant with EN81-70, EP 1598298A1 discloses adding a handicapped persons pushbutton to the touch screen. A top side of the handicapped persons pushbutton is clearly recognizable to visually handicapped persons by virtue of Braille characters with a relief height of at least 0.8 mm. Pushing the handicapped persons pushbutton with a pushing force of between 2.5 N and 5.0 N operates an area of the screen below the handicapped persons pushbutton and generates a cabin call.